Walking outside to the car to get grocery bags, I just start to close the car door, when I see this light moving really fast almost as if it was behind the clouds. I know it wasn't a spotlight because there are no stores in the direction of which this light kept on moving in a circular motion. Even though We live pretty close to the Philadelphia airport, this was not one of the lights that helps show the way. The way the light moved was pretty fast in an almost perfect circle, so there's no way it could have been a plane of any sort. Two more people who lived down the street walked out of their homes and had the same "What the heck is that?" look on their faces we all agreed that this truly has us stumped, any explaination you guys can help me with would be greatly appreciated.